Cryptococcus deneoformans is an opportunistic human fungal pathogen that mainly infects immunocompromised patients, including AIDs patients and patients with organ transplants. It infects approximately 280 thousand people and contributes to about 180 thousand deaths per year. Few strategies are available in treating Cryptococcosis. Dr. Heitman’s lab discovered two essential cell cycle regulating genes involved in the endoreplication pathway during C. deneoformans unisexual reproduction. This research focuses on developing strategies in studying these two essential genes. We generated expression constructs using the copper repressive promoter pCTR4-2 and the galactose-inducible promoter pUGE2 to modulate gene expression. We also used DAmP technique to reduce gene expression by disrupting the terminator sequence. By up- and down-regulating these genes, we would like to examine how perturbation of gene expression could impact C. deneoformans unisexual reproduction and other cellular processes. Study of essential genes also provides the opportunity for discovery of novel drug targets that are essential for cell growth. We are interested in testing how these genes impact the virulence of the pathogen by using DAmP alleles in different animal models. Based on this work, we could potentially broaden essential gene studies in both C. deneoformans and other fungal pathogens and provide hope in novel anti-fungal target discoveries.